When Sarah answered the door, Jon was wearing what should have been a simple pair of jeans and a T-shirt. But on him, it looked like a fashion statement. Without even trying, Jon had subtly accentuated all of his positive features, and his image wouldn't look out of place plastered across the entrance to a Forever 21.
Sarah, on the other hand, looked like a badly-stripped wire. Like a few bits of copper had come off with the insulation. Like current was still flowing, and contact with any conductive surface would result in a small explosion.
She invited Jon in and brought him upstairs as Samuel L. Jackson's voice could be heard from the living room.
"It's the damn milkshake. It's always been the milkshake. My milkshake brings all the boys to the yard."
Credits music began to play as Jon and Sarah arrived at the top of the stairs.
"I know what we're going to do," Sarah's eyes were wild as she continued to lead Jon down the hallway. "I figured it out at my party, you see."
"We need to be careful here, Sarah," Jon cautioned.
But Sarah wasn't listening. "If you say something, I don't think anything happens. And if I say something, nothing happens. But if I get someone else to say something, and you hear it, then you get your sister back, and I can go on with my life."
Sarah's assessment of the situation was not entirely correct.
"Hey, I came down here so that we could talk things out." Jon tried to slow Sarah down, but she just grabbed his wrist and began pulling him along.
"No," she snapped. "You came down here because you need to be in the room to hear the thing. I tried while you weren't here. It didn't work. Now," a glint shined in Sarah's eye as she put her other hand on a doorknob and turned, "Now you're here, and it will work."
"Jon!" Susan McMillan's voice rose in surprise as Sarah opened the door to reveal the master bedroom. "I'd heard you were sick. What are you doing here? Are you feeling alright now?"
Jon began to answer, but Sarah started talking before he could. "Mom. Would you say that I'm a good older sibling?"
"Of course!" Susan turned to her daughter. "You're a wonderful older sister!"
The fresh air of triumph filled Sarah's lungs, even as Jon's lungs emptied at the sound of the word "sister."
"After all," Susan continued, "you're a McMillan."
The world blinked out of existence for a moment. For just one moment, there was nothing. Just a field of darkness, with Jon and Sarah at the center. And in that moment, their lives re-wound themselves. Both teenagers grew younger, reversing in age from 18 to childhood to infancy, their bodies and their clothing shifting along the way. Just one moment, but in that long, infinite moment they both continued to shrink further still, reverting into fetuses and finally disappearing completely.
Then Jon returned. As a fetus, Jon returned. And that fetus grew, and it became a baby, and that baby became a toddler.
And then Sarah returned. Once again, as a fetus. And as the Sarah fetus grew, the Jon toddler continued to grow as well.
Soon there were two little girls, standing side-by-side, holding hands with one another, growing alongside one another.
As Jon approached his previous age of 18, however, it wasn't the same Jon that had stood in Susan McMillan's doorway just a moment and a half before. She was a girl, unambiguously, inside and out, but that wasn't all. Her hair color and skin tone matched Sarah's. The shape of her eyes were slightly different, the curve of her face. She was, with full certainty, a McMillan.
And she continued to grow. The changes were more subtle now. A slight fullness here, maybe an additional quarter-inch of height, a subtle look of maturity, as she settled into the age of 20.
And beside her, Sarah re-settled back to her original age of 18, looking not quite as she had a moment and a half before. Her changes were more subtle than Jon's, but they were there. All appearances of a raw wire ready to explode were gone: this version of Sarah had not spent the day watching some random boy turn into a supermodel. Some of the self-confidence was shaved away: she was now a middle child. But save for these subtle, almost-imperceptible differences, she was by-and-large the same girl she had always been.
And then the world blinked back into existence once again. And Sarah found herself back in the doorway to her mother's bedroom, her right hand held by her older sister, and her left hand held by her younger sister.
"Did you girls enjoy the movie?" Susan asked from her bed as she took in the sight of her three daughters, one by one.
She and her husband Richard were always going to name their first daughter Sarah, after Richard's grandmother, and the young woman who had once been a boy named Jon Gibson was now Susan's pride and joy, her spitting image, her daughter Sarah, who had followed in her mother's footsteps and was on her way to becoming a world-renowned model.
Susan's middle child was 18 and still in high school, and couldn't very well be named Sarah anymore if that name was already claimed by her older sister. Susan looked in the girl's eyes, and the name "Zoe" instinctively made itself known. Zoe had always looked up to her big sister Sarah, and was always trying to be as good at everything.
Finally Susan turned her eyes to her youngest girl, the 16 year-old who liked bats and spiders and wearing dark clothes, but who nevertheless was clearly a blonde little McMillan. Always trying to prove that she was her own person, separate from her two older sisters, even as she loved being a part of her family. And since there was already a Zoe in the family, her name materialized as Michelle.
It was this third child who chirped a gushing reply about how amazing the movie was, and how she'd learned so much about milkshakes, and the more words spilled out of her mouth, the more her older sisters' new realities fell heavily upon them.
After a few minutes, the newly-minted Michelle finished her analysis with a flippant "I think I'm going back to my room now," as she released the new Zoe's hand and ran down the hallway.
"I think we're turning in, too," the new Sarah closed the door as she lead a shell-shocked Zoe away.
Once they were far enough away that Susan couldn't hear them, Sarah wrapped her arms around her little sister and made shushing noises into her ear. "It's going to be okay. You're going to be fine. I'm going to take care of you."
Internally, Sarah was panicking as much as Zoe was. But she had to be a good big sister. She would always be Zoe's wonderful older sister.
